Hoplandrothrips graminicola sp. n., 2024

Okajima, Shûji & Masumoto, Masami, 2024, The genus Hoplandrothrips and its relatives (Thysanoptera: Phlaeothripidae) from Southeast Asia and Taiwan, Zootaxa 5489 (1), pp. 22-91 : 47-48

Hoplandrothrips graminicola sp. n.

( Figs 34–35 , 197–204 )

Female (macroptera). Distended body length: 2.4–2.5mm. Body brown. Antennal segments I and II brown, a little darker than head, segment III brown, with extreme base yellowish, scarcely paled externally, segments IV and V pale brown, with basal 1/4–1/3 yellowish, segment VI pale brown, with basal 1/5 yellowish, segments VII and VIII brown. All femora brown; all tibiae and tarsi yellow. Fore wing very weakly shaded. All prominent setae clear. Head ( Fig. 197 ) much longer than wide, about 1.5 times as long as wide, dorsal surface indistinctly sculptured with transverse striae, wrinkles or reticles, but almost smooth between eyes. Cheeks weakly rounded, strongly constricted behind eyes, serrated, with some minute setae, without stout basal setae. Postocular setae a little shorter than eyes, situated near cheeks, expanded. Eyes bulged, about 0.3 times as long as head; posterior ocelli close to eyes, distance between posterior ocelli much wider than a diameter of the ocellus, 30μm apart from each other in holotype. Antennae ( Fig. 199 ) about 1.7 times as long as head; segment VIII scarcely constricted at base; segment III about 1.63 times as long as wide in holotype, almost as long as segment IV, with three sense cones, segments VI and VII subequal in length. Mouth-cone short; maxillary stylets rather short, retracted to basal 1/3 of head, 17μm apart from each other in holotype. Pronotum almost smooth, 0.64 times as long head in holotype; am setae reduced, remaining four pairs of prominent setae expanded, pa longer than epim. Prosternal basantra absent, but membrane at the position of basantra roughly stiffened. Mesopresternum ( Fig. 201 ) divided into three sclerites. Mesonotum ( Fig. 200 ) weakly sculptured, metanotum very weakly sculptured or almost smooth; metanotal median pair of setae short and acute, 41–44μm apart from anterior margin, about 58μm apart from each other in holotype. Fore tarsal tooth directed laterally. Metathoracic sternopleural sutures long. Fore wings each with 5 duplicated cilia in holotype; three sub-basal setae ( Fig. 203 ) S1 and S2 expanded, S3 pointed, at least not distinctly expanded, shorter than S2. Pelta ( Fig. 202 ) bell- or hat-shaped, with rather broad lateral wings, sculptured with polygonal reticulation. Tergite IX posteromarginal setae slightly longer than tube, pointed. Tube ( Fig. 204 ) 0.54 times as long as head, 1.8 times as long as wide in holotype. Terminal setae longer than tube.

Measurements (holotype female in μm). Body length about 2420 (distended). Head length 250, from anterior margin of eyes 220, width across eyes 155, maximum width across cheeks 165; eyes length 77, width 50; diameter of posterior ocelli 18–20; postocular setae 70–72. Antenna total length 430, segments I–VIII length (width) as follows: 45 (42), 48 (32), 65 (40), 66 (37), 60 (28), 50 (23), 50 (22), 37 (12). Pronotum length 159, width 235. Setae on prothorax: am less than 10, aa 50, ml 25–30, pa 58–62, epim 45–52, cox 42. Fore wing length 780. Sub-basal wing setae: S1 35, S2 37, S3 25. Tergite IX setae: S1 155, S2 165. Tube length 135, maximum width 75; terminal setae 160.

Male (macroptera). Distended body length: about 2.3mm. Colour similar to female. Prothorax enlarged at least in large male; aa setae longer than pa. Fore legs stout; fore femur ( Fig. 198 ) enlarged, with a ventro-apical tubercle, fore tibia with an inner tubercle at basal 1/3, fore tarsal tooth stout. Fore wing with 4–7 duplicated cilia. Abdominal sternite VIII without pore plate; tergite IX S2 setae about 1/3 length of S1, intermediate setae longer than S2. Tube 0.55 times as long as head.

Measurements (paratype male in μm). Body length about 2280 (distended). Head length 250, from anterior margin of eyes 225, width across eyes 150, maximum width across cheeks 163; eyes length 75, width 50; postocular setae 65. Antenna total length 435, segments I–VIII length (width) as follows: 47 (40), 45 (33), 63 (38), 63 (37), 61 (29), 50 (23), 50 (20), 34 (10). Pronotum length 165, width 260. Setae on prothorax: am less than 10, aa 70, ml 40, pa 65, epim 50, cox 60. Fore wing length 800. Sub-basal wing setae: S1 40, S2 40, S3 40. Tergite IX setae: S1 155, S2 50. Tube length 137, maximum width 75; terminal setae 150.

Type series. Holotype: macropterous female, Thailand, Kamphaeng Saen Campus of Kasetsart University , on grass, 22.xii.1987, SO . Paratypes: Thailand, nr. Chiang Mai, Doi Suthep, 1 female, on grass, 1.ix.1991, TN & SO; same locality and habitat, 1 male, 2.ix.1992, SO; foot of Doi Suthep , 1 male, on grass, 24.viii.1992, SO .

Remarks. Two females and two males listed in the type series of H. graminicola were all found on grasses ( Poaceae ) in different occasions in Thailand, and it could well be recognised one of the grass-inhabiting species included in the nobilis -group. Although the head of this species is strongly constricted behind eyes and somewhat similar to that of Malacothrips species in appearance, most of the structures are shared with Hoplandrothrips species. It has the fore femur largely developed with a ventro-apical tubercle and the fore tibia with a sub-basal inner small tubercle at least in large male, the pelta bell-shaped, and abdominal tergite IX with a long and slender intermediate seta arising between S1 and S2 setae. From two other grass-inhabiting species, H. basantratus and H. samirseni , it is easily distinguished by the body uniformly brown, fore wing sub-basal setae S3 short and pointed (at least not distinctly expanded), and absence of prosternal basantra, although the membrane at the position of basantra is roughly stiffened.

Figures

FIGURES 29–42. Hoplandrothrips species. E. floresi sp. n. 29–30: (29) female; (30) male. E. formosae sp. n. 31–33: (31) female; (32) small male; (33) large male. E. graminicola sp. n. 34–35: (34) female; (35) male. H. laurencei sp. n. 36–37: (36) female; (37) male. H. obesametae 38–39: (38) female; (39) male. H. quinqueconus sp. n. 40–42: (40) female; (41) large male; (42) small male.

FIGURES 197–204. Hoplandrothrips graminicola sp. n. (197) Head and prothorax, female; (198) head and prothorax, large male; (199) antennal segments III–VIII, female; (200) metanotum, female; (201) prosternum and mesopresternum, female; (202) pelta and abdominal tergite II, female; (203) sub-basal wing setae, female; (204) tube, female.